diff --git a/widget/src/gtk2/nsWindow.cpp b/widget/src/gtk2/nsWindow.cpp
index b530521edf07..d51de863e24e 100644
--- a/widget/src/gtk2/nsWindow.cpp
+++ b/widget/src/gtk2/nsWindow.cpp
@@ -174,6 +174,7 @@ D_DEBUG_DOMAIN( ns_Window, "nsWindow", "nsWindow" );
 #endif
 
 using namespace mozilla;
+using namespace mozilla::widget;
 using mozilla::gl::GLContext;
 using mozilla::layers::LayerManagerOGL;